Overheating problem

[Wizard1]

I took my boat out this morning to do some fishing with my daughter and my motor overheated. It is a 1957 Evinrude Fastwin 18hp (15020), I had just finished replacing the seals in the lower unit and the water pump was replaced last year. I ran the motor in a barrel for about 10 to 15 mins Tuesday and it worked fine including the water spray from the pee-hole. This morning after it over heated I just trolled around on the trolling motor to let it cool off. After about 4 hours I started it back up and I noticed that no water was coming out of the pee-holes on the back of the motor. Does anyone have any idea what might have happened. I could not find anything covering or blocking the water pick up so I am at a loss here.:/

 

[Wizard1]

Re: Overheating problem

Ok, I found out why it overheated but I am at a loss to understand how it happened. I pulled the lower unit and then the water pump housing and found the water pump impeller in peices inside the housing. The impeller was only a little over one year old so I don't' under stand why it fell apart. Does anyone here have any ideas as to why an impeller might have just fell apart?:/

 

[emdsapmgr]

Re: Overheating problem

The easiest way to damage it is to run it out of the water. Possible that the impeller was from old stock and was already pretty dried out. If you run the engine in shallow sandy areas, it can ingest sand, which will prematurely kill any impeller. Did the impeller cup look smooth, or were there gouge lines from sand?

 

[Wizard1]

Re: Overheating problem

It looked smooth except for some pittinng but I ran my finger around it and could not feel anything. The rubber seems very plyablewhich is why I am having trouble figuring it out. If I some how installed the impeller backwards would it have worked for a little while then fall aprt?:/